Base station apparatus, terminal apparatus, communication method, and integrated circuit

ABSTRACT

Provided is a coding unit to determine the number of code block groups, divide an input bit sequence to code block segmentation into code block groups of the number of the code block groups, determine the number of code blocks for each of the code block groups, divide each of the code block groups into code blocks of the number of the code blocks, and apply channel coding to each of the code blocks.

TECHNICAL FIELD

The present invention relates to a base station apparatus, a terminalapparatus, a communication method, and an integrated circuit.

This application claims priority based on Japanese Patent ApplicationNo. 2016-filed on Jul. 8, 2016, the contents of which are incorporatedherein by reference.

BACKGROUND ART

Currently, Long Term Evolution (LTE)-Advanced Pro and New Radio (NR)technology are being studied and standardization is in progress in theThird Generation Partnership Project (3GPP), as a radio access schemeand a radio network technology for the fifth generation cellular system(NPL 1).

In the fifth generation cellular system, three services, including anenhanced Mobile BroadBand (eMBB) for realizing high-speed andlarge-capacity transmission, an Ultra-Reliable and Low LatencyCommunication (URLLC) for realizing low-delay and high-reliabilitycommunication, and a massive Machine Type Communication (mMTC) in whicha large number of machine-type devices such as Internet to Things (IoT)are connected, are required as assumed scenarios of service.

In NR, a Low Density Parity Check (LDPC) code and a low rate turbo codeare proposed in addition to the turbo code used in LTE-Advanced Pro (NPL2, NPL 3, NPL 4).

CITATION LIST Non Patent Literature

-   NPL 1: RP-161214 NTT DOCOMO, “Revision of SI: Study on New Radio    Access Technology”, June, 2016-   NPL 2: R1-164007, Samsung, “Flexibility of LDPC-Length, Rate and    IR-HARQ”, May, 2016-   NPL 3: R1-164183, Intel Corporation, “LDPC code design for NR”, May,    2016-   NPL 4: R1-164361, Ericsson, “Turbo Code Enhancements”, May, 2016

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide a terminal apparatus, abase station apparatus, a communication method, and an integratedcircuit efficiently, by a base station apparatus and a terminalapparatus in the above-described radio communication systems.

Solution to Problem

(1) To accomplish the object described above, aspects of the presentinvention are contrived to provide the following measures. Specifically,the base station apparatus according to one aspect of the presentinvention, includes a coding unit to determine the number of code blockgroups, divide an input bit sequence to code block segmentation intocode block groups of the number of the code block groups, determine thenumber of code blocks for each of the code block groups, divide each ofthe code block groups into code blocks of the number of the code blocks,and apply channel coding to each of the code blocks.

(2) In the base station apparatus according to an aspect of the presentinvention, the number of the code block groups is determined based onthe number of OFDM symbols.

(3) In the base station apparatus according to an aspect of the presentinvention, the number of code blocks in a first code block group isdetermined based on the number of resource elements included in one ormore OFDM symbols or SC-FDMA symbols corresponding to the first codeblock group.

(4) In the base station apparatus according to one aspect of the presentinvention, the input bit sequence to the code block segmentation is abit sequence in which a Cyclic Redundancy Check (CRC) sequence isattached to a transport block.

(5) In the base station apparatus according to one aspect of the presentinvention, the number of OFDM symbols or the number of SC-FDMA symbolsis determined based on information indicated by a higher layer or aphysical link control channel.

(6) The terminal apparatus according to one aspect of the presentinvention, includes a coding unit to determine the number of code blockgroups, divide an input bit sequence to code block segmentation intocode block groups of the number of the code block groups, determine thenumber of code blocks for each of the code block groups, divide each ofthe code block groups into code blocks of the number of the code blocks,and apply channel coding to each of the code blocks.

(7) In the terminal apparatus according to one aspect of the presentinvention, the number of the code block groups is determined based onthe number of OFDM symbols.

(8) In the terminal apparatus according to one aspect of the presentinvention, the number of code blocks in a first code block group isdetermined based on the number of resource elements included in one ormore OFDM symbols corresponding to the first code block group.

(9) In the terminal apparatus according to one aspect of the presentinvention, the input bit sequence to the code block segmentation is abit sequence in which a Cyclic Redundancy Check (CRC) sequence isattached to a transport block.

(10) In the terminal device according to one aspect of the presentinvention, the number of OFDM symbols is determined based on informationindicated by a higher layer or a physical link control channel.

(11) The communication method according to one aspect of the presentinvention, determines the number of code block groups, divides an inputbit sequence to code block segmentation into code block groups of thenumber of the code block groups, determines the number of code blocksfor each of the code block groups, divides each of the code block groupsinto code blocks of the number of the code blocks, and applies channelcoding to each of the code blocks.

(12) The integrated circuit according to one aspect of the presentinvention, includes a method for determining the number of code blockgroups, dividing an input bit sequence to code block segmentation intocode block groups of the number of the code block groups, determine thenumber of code blocks for each of the code block groups, divide each ofthe code block groups into code blocks of the number of the code blocks,and apply channel coding to each of the code blocks.

Advantageous Effects of Invention

According to an aspect of the present invention, a base stationapparatus and a terminal apparatus can efficiently communicate with eachother.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a concept of a radio communicationsystem according to the present embodiment.

FIGS. 2A to 2E are diagrams, each illustrating a concept of a subframeaccording to the present embodiment.

FIG. 3 is an example of a pseudo code for calculating the number of bitsto be input to code block segmentation.

FIG. 4 is an example of a pseudo code for determining the segmentationsize and the number of segments in code block segmentation.

FIG. 5 is an example of a pseudo code for determining the number offiller bits and the number of code block size in code blocksegmentation.

FIG. 6 is a diagram illustrating a value of each parameter in a turbointernal interleaver.

FIG. 7 is a diagram illustrating a configuration of an encoder with anoriginal coding rate of 1/3.

FIG. 8 is a block diagram for performing bit collection and ratematching.

FIG. 9 is a diagram illustrating the configuration of an encoder with anoriginal coding rate of 1/5.

FIG. 10 is a block diagram for performing bit collection and ratematching.

FIG. 11 is an example of a flow for performing a channel coding.

FIG. 12 is an example of a flow for performing a channel coding.

FIG. 13 is a diagram illustrating a concept of code block segmentation.

FIG. 14 is an example of a flow for performing a channel coding.

FIG. 15 is an example of a pseudo code for calculating the number ofbits to be input to code block segmentation.

FIG. 16 is an example of pseudo codes for determining the segmentationsize and the number of segments in code block segmentation.

FIG. 17 is a schematic block diagram illustrating a configuration of aterminal apparatus 1 according to the present embodiment.

FIG. 18 is a schematic block diagram illustrating a configuration of abase station apparatus 3 according to the present embodiment.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below.

FIG. 1 is a conceptual diagram of a radio communication system accordingto the present embodiment. In FIG. 1, a radio communication systemincludes terminal apparatuses 1A to 1C and a base station apparatus 3.Hereinafter, the terminal apparatuses 1A to 1C are each also referred toas a terminal apparatus 1.

The terminal apparatus 1 is also called a user terminal, a mobilestation device, a communication terminal, a mobile device, a terminal,User Equipment (UE), and a Mobile Station (MS). The base stationapparatus 3 is also referred to as a radio base station apparatus, abase station, a radio base station, a fixed station, a NodeB (NB), anevolved NodeB (eNB), a Base Transceiver Station (BTS), a Base Station(BS), a NR Node B (NR NB), a NNB, a Transmission and Reception Point(TRP).

Referring to FIG. 1, in the radio communication between the terminalapparatus 1 and the base station apparatus 3, Orthogonal FrequencyDivision Multiplexing (OFDM) including Cyclic Prefix (CP),Single-Carrier Frequency Division Multiplexing (SC-FDM), DiscreteFourier Transform Spread OFDM (DFT-S-OFDM), or Multi-Carrier CodeDivision Multiplexing (MC-CDM), may be used.

Also, in FIG. 1, in the radio communication between the terminalapparatus 1 and the base station apparatus 3, Universal-FilteredMulti-Carrier (UFMC), Filtered OFDM (F-OFDM), Windowed OFDM, orFilter-Bank Multi-Carrier (FBMC), may be used.

In the present embodiment, the description is made with OFDM symbolsusing OFDM as a transmission scheme, but a case of using anothertransmission scheme described above is also included in one aspect ofthe present invention.

Also, in the radio communication between the terminal apparatus 1 andthe base station apparatus 3 in FIG. 1, the above-described transmissionscheme that does not use CP, or that has zero padding instead of CP, maybe used. Further, CP and zero-padding may be attached to both forwardand backward.

Referring to FIG. 1, in the radio communication between the terminalapparatus 1 and the base station apparatus 3, Orthogonal FrequencyDivision Multiplexing (OFDM) including Cyclic Prefix (CP),Single-Carrier Frequency Division Multiplexing (SC-FDM), DiscreteFourier Transform Spread OFDM (DFT-S-OFDM), or Multi-Carrier CodeDivision Multiplexing (MC-CDM), may be used.

In FIG. 1, the following physical channels are used for radiocommunication between the terminal apparatus 1 and the base stationapparatus 3.

-   -   Physical Broadcast CHannel (PBCH)    -   Physical Control CHannel (PCCH)    -   Physical Shared CHannel (PSCH)

The PBCH is used for notifying an important information block (MasterInformation Block (MIB), Essential Information Block (EIB)) includingimportant system information necessary for the terminal apparatus 1.

PCCH is used for transmitting Uplink Control Information (UCI) in a caseof uplink radio communication (radio communication from the terminalapparatus 1 to the base station apparatus 3). Here, the uplink controlinformation may include Channel State Information (CSI) used to indicatea downlink channel state. The uplink control information may includeScheduling Request (SR) used to request an UL-SCH resource.

The uplink control information may include Hybrid Automatic RepeatreQuest ACKnowledgment (HARQ-ACK). The HARQ-ACK may represent HARQ-ACKfor downlink data (Transport block, Medium Access Control Protocol DataUnit (MAC PDU), Downlink-Shared Channel (DL-SCH)).

In a case of downlink radio communication (radio communication from thebase station apparatus 3 to the terminal apparatus 1), PCCH is used fortransmitting Downlink Control Information (DCI). Here, one or more DCIs(may be referred to as DCI formats) are defined for a transmission ofdownlink control information. In other words, a field for the downlinkcontrol information is defined as a DCI and is mapped to informationbits.

For example, a DCI including information for indicating whether a signalincluded in the scheduled PSCH is a downlink radio communication oruplink radio communication, may be defined as a DCI.

For example, a DCI including information for indicating a downlinktransmission period included in the scheduled PSCH, may be defined as aDCI.

For example, a DCI including information for indicating an uplinktransmission period included in the scheduled PSCH, may be defined as aDCI.

For example, a DCI including information for indicating the timing oftransmitting the HARQ-ACK for the scheduled PSCH (for example, thenumber of symbols from the last symbol included in the PSCH to theHARQ-ACK transmission), may be defined as a DCI.

For example, a DCI including information for indicating a downlinktransmission period, a gap, and an uplink transmission period includedin the scheduled PSCH, may be defined as a DCI.

For example, a DCI to be used for scheduling one downlink radiocommunication PSCH in one cell (transmission of one downlink transportblock), may be defined as a DCI.

For example, a DCI to be used for scheduling one uplink radiocommunication PSCH in one cell (transmission of one uplink transportblock), may be defined as a DCI.

Here, the DCI includes information related to the scheduling of the PSCHin a case that the PSCH includes an uplink or a downlink. Here, thedownlink DCI is also referred to as downlink grant or downlinkassignment. Here, the uplink DCI is also referred to as uplink grant oruplink assignment.

PSCH is used for transmitting uplink data (Uplink Shared CHannel(UL-SCH)) or downlink data (Downlink Shared CHannel (DL-SCH)) fromMedium Access (Medium Access Control (MAC)). Furthermore, in a case ofdownlink, the PSCH is also used for transmission of System Information(SI) and Random Access Response (RAR) and the like. In a case of uplink,the PSCH may be used for transmission of HARQ-ACK and/or CSI along withthe uplink data. Furthermore, the PSCH may be used to transmit CSI onlyor HARQ-ACK and CSI only. In other words, the PSCH may be used totransmit the UCI only.

Here, the base station apparatus 3 and the terminal apparatus 1 exchange(transmit and/or receive) signals with each other in their respectivehigher layers. For example, the base station apparatus 3 and theterminal apparatus 1 may transmit and/or receive, in a Radio ResourceControl (RRC) layer, RRC signaling (also referred to as a Radio ResourceControl message (RRC message) or Radio Resource Control information (RRCinformation)). The base station apparatus 3 and the terminal apparatus 1may transmit and receive a Medium Access Control (MAC) control elementin a MAC layer, respectively.

Here, the RRC signaling and/or the MAC control element is also referredto as higher layer signaling.

The PSCH may be used to transmit the RRC signaling and the MAC controlelement. Here, the RRC signaling transmitted from the base stationapparatus 3 may be signaling common to multiple terminal apparatuses 1in a cell. The RRC signaling transmitted from the base station apparatus3 may be signaling dedicated to a certain terminal apparatus 1 (alsoreferred to as dedicated signaling). In other words, terminalapparatus-specific (UE-specific) information may be transmitted throughsignaling dedicated to the certain terminal apparatus 1. The PSCH may beused for transmitting UE capability in the uplink.

Whereas PCCH and PSCH use the same designation for downlink and uplink,different channels may be defined for downlink and uplink.

In FIG. 1, the following downlink physical signals are used for downlinkradio communication. Here, the downlink physical signals are not used totransmit the information output from the higher layers but is used bythe physical layer.

-   -   Synchronization Signal (SS)    -   Reference Signal (RS)

The synchronization signal is used for the terminal apparatus 1 to takesynchronization in the frequency domain and the time domain in thedownlink. Here, the synchronization signal may be used by the terminalapparatus 1 for selecting precoding or beam, in a case that precoding orbeamforming is performed by the base station apparatus 3.

The Reference Signal is used for the terminal apparatus 1 to performpropagation path compensation of a physical channel. Here, the referencesignal may also be used in order for the terminal apparatus 1 tocalculate the downlink CSI. In addition, the reference signal may beused for fine synchronization with which numerologies for radioparameters, subcarrier intervals, and the like can be used, or windowsynchronization of FFT can be performed.

The subframe will be described below. In the present embodiment, it isreferred to as a subframe, but it may be referred to as a resource unit,a radio frame, a time section, a time interval, or the like.

FIGS. 2A to 2E each illustrate an example of a subframe (subframe type).In the figure, reference sign D represents a downlink and reference signU represents an uplink. As shown in the figure, within a certain timeperiod (for example, a minimum time period that must be allocated to oneUE in the system) may include one or more of the followings:

-   -   downlink part (duration)    -   gap    -   uplink part (duration).

FIG. 2A illustrates an example in which an entire time period (Forexample, it may be referred to such as a minimum unit of time resourcethat can be allocated to one UE, or a time unit.

It may also be referred to as a time unit in which a plurality ofminimum units of time resource are bundled.) is used for downlinktransmission. In FIG. 2B, uplink scheduling is performed, for example,through the PCCH in the first time resource, and the uplink signal istransmitted after a gap for the processing delay of the PCCH, theswitching time from the downlink to the uplink, and generation of atransmission signal. In FIG. 2C, the first time resource is used fortransmitting the downlink PCCH and/or the downlink PSCH, and PSCH orPCCH is transmitted after a gap for the processing delay, the switchingtime from the downlink to the uplink, and generation of a transmissionsignal. Here, as one example, the uplink signal may be used fortransmission of HARQ-ACK and/or CSI, that is UCI. In FIG. 2D, the firsttime resource is used for transmitting the downlink PCCH and/or thedownlink PSCH, and uplink PSCH and/or PCCH is transmitted after a gapfor the processing delay, the switching time from the downlink to theuplink, and generation of a transmission signal. Here, as one example,the uplink signal may be used for transmitting uplink data, that is,UL-SCH. FIG. 2E is an example in which an entire time period is used foruplink transmission (uplink PSCH or PCCH).

The above-described downlink part and uplink part may be constituted bya plurality of OFDM symbols like LTE.

Here, the resource grid may be defined by a plurality of subcarriers,and a plurality of OFDM symbols or a plurality of SC-FDMA symbols. Thenumber of subcarriers constituting one slot may depend on a cellbandwidth. The number of OFDM symbols or SC-FDMA (SC-FDM) symbolsconstituting one downlink part, or uplink part may be one or more, ortwo or more. Here, each element within the resource grid is referred toas a resource element. The resource element may be identified by asubcarrier number, and an OFDM symbol number or SC-FDMA symbol number.

Channel coding will be described below.

Code block segmentation is performed to an information bit sequence(which may be referred to as a transport block) transmitted from ahigher layer.

It is assumed that the input bit sequence to code block segmentation isb_(k) (k=0, 1, . . . , B−1, where B is the number of input bits andB>0). In a case that B is greater than the maximum code block size Z,segmentation of the input bit sequence is applied and L bit CyclicRedundancy Check (CRC) sequence is attached to each code block. The CRCsequence length L is, for example, 16 or 24, and the maximum code blocksize Z is, for example, 6144 bits or 8192 bits.

In a case that the calculated filler bit number F is not 0, the fillerbit is attached to the head of the first block. However, in a case thatthe number B of input bits is smaller than 40, the filler bit isattached to the head of the code block. The filler bit is set to Null atthe input to the encoder.

FIG. 3 illustrates a pseudo code in which the number of code blocks isdetermined. The length L of the CRC sequence and the number of codeblocks, C, are determined by the pseudo code shown in FIG. 3, where A isthe length of the CRC sequence and may be different depending on thechannel, and B′ is the number of bits in a case that a CRC sequence isattached to the number of input bits.

In a case that C is not 0, bits output from code block segmentation aredenoted by c_(k) (k=r 0, r 1, . . . r (K_(r)−1)), where r is the codeblock number and K_(r) is the number of bits for the code block numberr.

FIGS. 4 and 5 illustrate a pseudo code for determining a segment sizeand the number of segments in code block segmentation, and a pseudo codefor determining a filler bit and a code block size, respectively. FIG. 6illustrates a table for determining K₊ and K⁻ in FIGS. 4 and 5.

FIG. 7 illustrates a configuration of a turbo encoder having an originalcoding rate of 1/3. In FIG. 7, the turbo coding scheme is a ParallelConcatenated Convolutional Code (PCCC) having two constituent encoders,each having eight-states (constraint length 4) and a turbo code internalinterleaver. In the embodiment, whereas the constituent encodersrealized by the convolution operation are connected in parallel, a blockcode such as LDPC may also be applied, or a configuration may be usedthat serially concatenate a Serial Concatenated Convolutional Code(SCCC) or the constituent encoder realized by the serially concatenatedconvolution operation with the block code. In the following embodiments,the coding rate 1/3 in turbo coding is referred to as the originalcoding rate (mother rate, mother coding rate), and the actual codingrate, determined by the transport block size and the number of codewordbits after rate matching, is referred to as the transmission codingrate.

In FIG. 7, + denotes an exclusive OR, and D denotes a shift register.The initial value of the shift register is 0.

The k-th information bit c_(k) is input to the first constituent encoderand input to the turbo code internal interleaver 10 as well. In theturbo code internal interleaver 10, an interleaver is performed tointerchange the order of the input bits, and c′_(k) is output. c′_(k) isinput to the second constituent encoder. The information bit is each bitincluded in a transport block (which is also referred to as a code blockgroup, a code block, or the like), and the information bit may also bereferred to as an information source bit, a source bit, or the like.

Turbo code internal interleaver 10 may use random interleaving or blockinterleaving. Also, a Quadratic Permutation Polynomial (QPP) interleavermay be used. The QPP interleaver is denoted by Equation (1) with respectto the bit length K:Π(i)=(f ₁ ·i+f ₂ ·i ²)mod K  [Equation 1]

where mod is a modulo operation where Π(i) means that the bit to whichthe i-th bit is input is the Π(i)-th output, and f₁ and f₂ are theparameters, given in FIG. 5, which is defined by the number of inputbits K and of which the values are defined by FIG. 5.

For c_(k), in the first constituent encoder 11, z_(k) is output by thelogical operation shown in the figure, by using the codeword x_(k)output as it is and the bit held in the shift register for every timethe bit is input. For c′_(k), in the second constituent encoder 12,z′_(k) is output by the logical operation shown in the figure, by usingthe bit held in the shift register for every time the bit is input.

x′_(k) output from the switch of the first constituent encoder and thesecond constituent encoder can terminate all of the registers to zero inthe state transition of the shift register.

The turbo-coded codeword d^((n)) _(k) (n=0, 1, 2) for the k-thinformation bit is denoted by the following equation respectively, withthe assumption that the number of input information bits (code blocklength) is K (k=0, 1, 2, . . . , K−1).d _(k) ⁽⁰⁾ =x _(k)d _(k) ⁽¹⁾ =z _(k)d _(k) ⁽²⁾ =z′ _(k)  [Equation 2]

The termination bits d^((n)) _(k) (n=0, 1, 2 and k=K, K+1, K+2, K+3) arerepresented by Equations (3) to (6).d _(K) ⁽⁰⁾ =x _(K)d _(K) ⁽¹⁾ =z _(K)d _(K) ⁽²⁾ =x _(K+1)  [Equation 3]d _(K+1) ⁽⁰⁾ =z _(K+1)d _(K+1) ⁽¹⁾ =z _(K+2)d _(K+1) ⁽²⁾ =z _(K+2)  [Equation 4]d _(K+2) ⁽⁰⁾ =x′ _(K)d _(K+2) ⁽¹⁾ =z′ _(K)d _(K+2) ⁽²⁾ =x′ _(K+1)  [Equation 5]d _(K+3) ⁽⁰⁾ =z′ _(K+1)d _(K+3) ⁽¹⁾ =x′ _(K+2)d _(K+3) ⁽²⁾ =z′ _(K+2)  [Equation 6]

FIG. 8 illustrates an example of a block diagram for rate matching. Theorder of the turbo-coded codeword d^((n)) _(k) is interchanged throughthe subblock interleaver 20, and v^((n)) _(k) is output. For v^((n))_(k), the circular buffer w_(k) (k=0, 1, . . . , K_(Π)) is obtained bythe bit collection unit 21. Here, w_(k) is represented by Equation (7),and the circular buffer length K_(w)=3K_(Π):w _(k) =v _(k) ⁽⁰⁾w _(k) _(Π) _(+2k) =v _(k) ⁽¹⁾w _(k) _(Π) _(+2k+1) =v _(k) ⁽²⁾  [Equation 7]

where K_(Π) is the number of bits required for the subblock interleaver,R is the minimum value that C×R satisfies K or more, that is K_(Π)=C×R,with the assumption that the subblock interleaver length is C and thenumber of blocks to which the subblock interleaver is applied is R.

Here, with the assumption that v⁽⁰⁾ _(k) is an organization bit, v⁽¹⁾_(k) is a codeword bit from the first constituent encoder, and v⁽²⁾ _(k)is a codeword bit from the second constituent encoder, the codewords(code bits) input to the circular buffer are arranged in order with theorganization bit being first arranged, and input such that the codewordbit from the first constituent encoder and the codeword bit from thesecond constituent encoder are alternately arranged.

After that, the codeword e_(k) is output from the circular buffer by therate matching 22 according to the value of the redundancy version.

FIG. 9 illustrates a configuration of a turbo encoder having an originalcoding rate of 1/5. FIG. 9 illustrates a configuration of a ParallelConcatenated Convolutional Code (PCCC) in which component coders ofconstraint length 4 are concatenated in parallel as one example.

In FIG. 9, + denotes an exclusive OR, and D denotes a shift register.The k-th information bit c_(k) is input to the first constituent encoderand input to the turbo code internal interleaver 30 as well. In theturbo code internal interleaver 30, an interleaver is performed tointerchange the order of the input bits, and c′_(k) is output. c′_(k) isinput to the second constituent encoder.

The turbo code internal interleaver 30 may be random interleave or blockinterleave, and may use a Quadratic Permutation Polynomial (QPP)interleaver.

For c_(k), in the first constituent encoder 31, z_(k) and y_(k) areoutput by the logical operation shown in the figure, by using thecodeword x_(k) output as it is and the bit held in the shift registerfor every time the bit is input. For c′_(k), in the second constituentencoder 32, z′_(k) and y′_(k) are output by the logical operation shownin the figure, by using the bit held in the shift register for everytime the bit is input.

The output x′_(k) output from the switch of each constituent encoder andthe second constituent encoder can terminate all of the registers tozero in the state transition of the shift register.

The turbo-coded codeword d^((n)) _(k) (n=0, 1, . . . , 4) for the k-thinformation bit is denoted by Equation (8), with the assumption that thenumber of input information bits (code block length) is K (k=0, 1, 2, .. . , K−1).d _(k) ⁽⁰⁾ =x _(k)d _(k) ⁽¹⁾ =z _(k)d _(k) ⁽²⁾ =y _(k)d _(k) ⁽³⁾ =z′ _(k)d _(k) ⁽⁴⁾ =y′ _(k)  [Equation 8]

Likewise, the termination bits d^((n)) _(k) (n=0, 1, . . . , 4 and k=K,K+1, K+2, K+3) are given by code bits output by switching so that all ofthe shift registers become zero.

FIG. 10 illustrates an example of a block diagram for rate matching. Theorder of the turbo-coded codeword d^((n)) _(k) is interchanged throughthe subblock interleaver 40, and v^((n)) _(k) is output. For v^((n))_(k), the circular buffer w_(k) (k=0, 1, . . . , K_(Π)) is obtained bythe bit collection unit 41. Here, w_(k) is denoted by Equation (9), andthe circular buffer length Kw=5 K_(Π):w _(k) =v _(k) ⁽⁰⁾w _(K) _(Π) _(+2k) =v _(k) ⁽¹⁾w _(K) _(Π) _(+2k+1) =v _(k) ⁽²⁾w _(3K) _(Π) _(+2k) =v _(k) ⁽²⁾w _(3K) _(Π) _(+2k+1) =v _(k) ⁽⁴⁾  [Equation 9]

where K_(Π) is the number of bits required for the subblock interleaver,R is the minimum value that C×R satisfies K or more, that is K_(Π)=C×R,assuming that the subblock interleaver length is C and the number ofblocks to which the subblock interleaver is applied is R.

Here, assuming that v⁽⁰⁾ _(k) is an organization bit, v⁽¹⁾ _(k) and v⁽²⁾_(k) are codeword bits from the first constituent encoder, and v⁽³⁾ _(k)and v⁽⁴⁾ _(k) are a codeword bits from the second constituent encoder,the codewords (code bits) input to the circular buffer are arranged inorder with the organization bits first, and v⁽²⁾ _(k) and v⁽⁴⁾ _(k) areinput alternately, so that the codeword bits from the first constituentencoder and the codeword bits from the second constituent encoder, v⁽¹⁾_(k) and v⁽³⁾ _(k), are alternately arranged.

After that, the codeword e_(k) is output from the circular buffer by therate matching 42 according to the value of the redundancy version.

In the present embodiment, the original coding rate of 1/3 and theoriginal coding rate of 1/5 have been described respectively, however,they may be switched according to the original coding rate of thecodeword to be transmitted, or only channel coding of the originalcoding rate of 1/5 may be used.

Further, the base station apparatus 3 may signal which original codingrate is to be used for coding, to the terminal apparatus 1. For example,the base station apparatus 3 may transmit the information used toindicate that coding is being performed by using the original codingrate 1/3. Also, the base station apparatus 3 may transmit theinformation used to indicate that coding is being performed by using theoriginal coding rate 1/5. In other words, the original coding rate thatis being used for coding may be given, based on the informationtransmitted by the base station apparatus 3. Also, the coding scheme,among a plurality of coding scheme (such as turbo code, convolutionalcode, LDPC, polar code, Reed-Solomon code, outer erasure code), to beapplied may be signaled. Further, the coding scheme that is applied tothe transport block may be specified by specifications or the like. Forexample, the first coding scheme may be applied to the first transportblock and the second coding scheme may be applied to the secondtransport block.

A method of coding a transport block with respect to the number ofdecodable OFDM symbols or the number of decodable SC-FDMA symbols willbe described below. (Scaling the transport block size according to thenumber of symbols in the symbol group)

FIG. 11 illustrates a flowchart in a case that the number of OFDMsymbols or the number of SC-FDMA symbols included in the downlink partand the uplink part, is X.

First, in step 50, the transport block size is determined based on thechannel state (for example, the CSI information measured by the terminalapparatus in a case of downlink, the uplink channel state measured bythe base station apparatus based on the uplink sounding signal in a caseof uplink), and the number of symbols included in the downlink part orthe uplink part used for transmitting the PSCH.

For example, in the downlink PSCH, in a case that the CQI included inthe CSI reported from the terminal apparatus is 16 QAM and theutilization efficiency is 3 (which is the number of bits that can betransmitted per one hertz), the transmission coding rate multiplied by1024 is 768, and the transmission coding rate r=3/4. At this time,assuming that the number of modulation symbols that can be mapped in theX symbol is Y, the transport block size to which the transmittable CRCis attached is represented by Equation (10):B′=floor(MYr)  [Equation 10]

where floor(x) is a floor function, and is the largest integer that isless than or equal to x, B′ is the number of information bits beforechannel coding, M is the number of bits that can be transmitted per onemodulation symbol, and r is a transmission coding rate. The value of Mvaries depending on the modulation scheme, and for example, M=1, M=2,M=4, M=6, M=8, M=10 correspond to BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM,1024 QAM, respectively.

At this time, in a case that the number of transport blocks isdetermined, B′ may be determined as the value B that is closest to B′from the predefined table, or the value B that is closest to B′ definedby the number X of symbols. Further, the transport block size B may bedetermined after calculating the number of code blocks from B′ inadvance, or B′ may be used as it is for code block segmentation. It may,or may not, be assumed that the CRC bit is included in the B′ describedabove.

For example, in a case of Y=1024, M=4, r=3/4, B′ is 3072 and B isdetermined from 3072 (3070, for example), then the processing proceedsto, for example, the step of the code block segmentation describedabove.

From the determined value B, code block segmentation and attachment ofCRC to each code block are performed in step 51, and channel coding isperformed in step 52. Subsequently, in step 51, combining of bitsequences such as subblock interleaving and rate-matching are performed.

Here, the determination of the transport block size according to thepresent embodiment may be either a turbo code or a Low Density ParityCheck code (LDPC).

The transport block size according to the present embodiment may bedetermined by the Mediation Access Control (MAC) layer based on thenumber X of symbols.

(Coding the Transport Block for Each Symbol Group)

Another method of determining a code block according to the presentembodiment will be described below. Whereas the transport block size ischanged in the above-described example, the code block size is changedbased on the number X of OFDM symbols or the number X of SC-FDMA symbolsin the following method.

FIG. 12 illustrates an example of a flowchart of the determinationmethod. In step 60, the transmission apparatus (base station apparatusor terminal apparatus) determines the number of bits (size) for codeblock group segmentation from the number of modulation symbols (or thenumber of resource elements) that can be mapped to X symbol. Forexample, based on the number of modulation symbols (number of resourceelements) corresponding to X symbols among the symbols (N symbols) to beused for transmitting the transport block, the number of bits (size) forcode block group segmentation with respect to the transport block, maybe given. That is, the transport block may be divided into the givennumber of bits (size) by code block group segmentation.

Here, the X symbols (X is the number of symbols) may be defined inadvance by a specification or the like. Also, the X symbols may be givenbased on the information transmitted by the base station apparatus 3.For example, the number of X symbols may be 1, 2, 4, and/or 7.

For example, in the downlink PSCH, in a case that the CQI included inthe CSI reported from the terminal apparatus is 16 QAM and theutilization efficiency is 3 (which is the number of bits that can betransmitted per one hertz), the transmission coding rate multiplied by1024 is 768, and the transmission coding rate r=3/4. At this time,assuming that the number of modulation symbols that can be mapped in theX symbol is Y, the number of transmittable bits B″ before channel codingis denoted by Equation (11):B″=floor(MYr)  [Equation 11]

where floor(x) is a floor function, and is the largest integer that isless than or equal to x. B″ obtained in this way is treated as thenumber of bits of one code block group. For example, in a case that thetransport block size is 12288 bits and B″ is 7000 bits, code blocksegmentation is performed in step 61, by using 7000 bits and 5288 bitsas units for code block division, instead of creating two code blocks of6144 bits for example. That is, in this example, the transport blocksize is 12288 bits, and the number of bits for code block groupsegmentation is 7000 bits and 5288 bits. That is, the number of codeblock groups is two. Further, code block segmentation is applied to eachof 7000 bit code block group and 5288 bit code block group.

Subsequently, channel coding is performed in step 62, and codewordcombining and rate matching are performed in step 63.

FIG. 13 illustrates the concept of applying codeword segmentation fromthe transport block according to the embodiment.

A CRC is attached to a transport block, and the transport block isdivided into a plurality of code block groups (B″ bits) based on thenumber of resource elements included in the X symbol.

Code block segmentation is applied to each of code block groups.

In the code block segmentation, the size of the code block is determinedsuch that the segment size becomes a predetermined value.

FIG. 14 illustrates an example of a flow for code block groupsegmentation in step 60.

First, in step 70, the number M of codeword bits (the number of bitsafter channel coding) is calculated from the number X of symbols and/orthe number of resource elements. For example, assuming the number ofresource elements included in the X-OFDM symbols or the X-SC-FDMAsymbols is Y, the number Q of transmittable bits in one modulationsymbol may be used to denote M=Y×Q.

Next, in step 71, the number of bits of the code block group for whichthe number of codeword bits after rate matching becomes M, iscalculated. For example, assuming that the transmission coding rate usedfor transmission such as CSI reporting or sounding is r, the number B″of bits included in the code block group is represented as B″=floor(Mr),where floor(x) is a floor function, and is the largest integer that isless than or equal to x.

Finally, the transport block size is divided into code block groups instep 72. Assuming that the number of bits included in the 1-th codeblock group is K₁ and the number of code block groups is C₁, they aredenoted by Equation (12):

$\begin{matrix}{{C_{l} = {{ceil}\left( {A/M} \right)}}{B^{''} = \left\{ \begin{matrix}{{floor}({Mr})} & {l \neq C_{l}} \\{A - {\left( {C_{l} - 1} \right){{floor}({Mr})}}} & {l = C_{l}}\end{matrix} \right.}} & \left\lbrack {{Equation}\mspace{14mu} 12} \right\rbrack\end{matrix}$

where ceil(x) is a ceiling function, and is the smallest integer that isgreater than or equal to x, floor(x) is a floor function, and is thelargest integer that is less than or equal to x, and a is transportblock size. Here, the remainder obtained by dividing the transport blocksize by the floor(Mr) bit is regarded as one code block group for thefraction, but other processing of fraction may be used. For example, ina case that the transport block is divided for each floor(Mr) bit untilthe remaining bits become between the floor(Mr) bit and 2×floor(Mr), thetransport block segmentation may be performed by causing the remainingtransport block to be divided in two.

FIGS. 15 and 16 respectively illustrate a pseudo code for determiningsegment size and number of segments in code block segmentation in step61, and a pseudo code for determining filler bits and code block size.

FIGS. 15 and 16 illustrate a case of using the turbo code as oneexample, and the difference from FIG. 4 is that the value is determinedby B″ in place of B′.

First, the first segmentation size K. is set to the smallest value amongthe values of K in FIG. 5, the values of K satisfying a relationship inwhich the value of the number of code blocks×K is B″ or more.

In a case that the number of code blocks, C, is 1, the number of codeblock sizes of length K₊ is set to C₊=1, and K⁻=0 and C⁻=0.

In a case that the number of code blocks, C, is greater than 1, thesecond segmentation size K₊ is set to the greatest value that is smallerthan K₊ among Ks in FIG. 5.

After that, segment sizes C⁻ and C₊ are determined by the equation inFIG. 14. Finally, the number of the filler bits is determined, and thesize K_(r) of the r-th code block is determined.

In a case of LDPC, the size of rows or columns of a check matrix or agenerator matrix of LDPC, which is predefined or defined by a code blockor a transport block size, may be set as a code block size K_(r). In thecase of LDPC, processing such as determination of the number of fillerbits may be omitted.

CRC (CRC parity bit) may be attached (granted) to the code block group.The CRC may not be attached to the code block group. The HARQ bit may bereported for each code block group. The HARQ bit may be reported foreach transport block.

In a case that the number of code blocks, C, is greater than 1, thesecond segmentation size K₊ is set to the greatest value that is smallerthan K₊ among Ks in FIG. 5.

After that, segment sizes C⁻ and C₊ are determined by the equation inFIG. 14. Finally, the number of the filler bits is determined, and thesize K_(r) of the r-th code block is determined.

In a case of LDPC, the size of rows or columns of a check matrix or agenerator matrix of LDPC, which is predefined or defined by a code blockor a transport block size, may be set as a code block size K_(r). In thecase of LDPC, processing such as determination of the number of fillerbits may be omitted.

As another method of calculating B″, B″ is determined by dividing thetransport block transmitted (supplied) from the higher layer by a unitof the number X of OFDM symbols or the number X of SC-FDMA symbols X,the number X being a unit for decoding.

Specifically, in step 70, B″ is denoted by Equation (13) for example,where the number of allocated OFDM symbols or the number of allocatedSC-FDMA symbols is N, the number of OFDM symbols or the number ofSC-FDMA symbols, as a unit for decoding, is X, and the transport blocksize is T.

$\begin{matrix}{B^{''} = \left\{ \begin{matrix}{{{floor}\left( {T/\left( {N/X} \right)} \right)} + 1} & {l \leq {{mod}\left( {T,C_{l}} \right)}} \\{{floor}\left( {T/\left( {N/X} \right)} \right)} & {{{mod}\left( {T,C_{l}} \right)} < l \leq C_{l}}\end{matrix} \right.} & \left\lbrack {{Equation}\mspace{14mu} 13} \right\rbrack\end{matrix}$

However, mod (A, B) is a remainder obtained by dividing A by B. Here,the calculation is performed by a method of dividing such that thedifference in the number of bits between code block groups is minimized,but other methods of dividing may be used. Further, the number X ofdecodable OFDM symbols or the number X of decodable SC-FDM symbol X issmaller than the number N of allocated OFDM symbols or the number N ofallocated SC-FDM symbols.

In a case of LDPC, the generator matrix or the check matrix may bedetermined or selected based on B″ or code block length.

One aspect of the present embodiment may be operated in a carrieraggregation or a dual connectivity of a Radio Access Technology (RAT)such as LTE and LTE-A/LTE-A Pro. At this time, one aspect of the presentembodiment may be used in some or all of the cells, cell groups,carriers, or carrier groups, such as a Primary Cell (PCell), a SecondaryCell (SCell), a Primary Secondary Cell (PSCell), a Master Cell Group(MCG), a Secondary Cell Group (SCG), or the like. It may also be used instand-alone operating independently.

The transport block according to the present embodiment can also beextended to be assigned to a plurality of subframes and time units.Further, the number X of OFDM symbols or the number X of the SC-FDMsymbols may be greater than the number N of allocated OFDM symbols.

Configurations of apparatuses according to the present embodiment willbe described below. Here, an example is described, in which CP-OFDM isapplied as the downlink radio transmission scheme and CP DFTS-OFDM(SC-FDM) is applied as the uplink radio transmission scheme.

FIG. 17 is a schematic block diagram illustrating a configuration of theterminal apparatus 1 according to the present embodiment. As illustratedin FIG. 9, the terminal apparatus 1 is configured to include a higherlayer processing unit 101, a controller 103, a receiver 105, atransmitter 107, and a transmit and/or receive antenna 109. Furthermore,the higher layer processing unit 101 is configured to include a radioresource control unit 1011, a scheduling information interpretation unit1013, and a Channel State Information (CSI) report control unit 1015.Furthermore, the receiver 105 is configured to include a decoding unit1051, a demodulation unit 1053, a demultiplexing unit 1055, a radioreception unit 1057, and a measurement unit 1059. The transmitter 107 isconfigured to include a coding unit 1071, a modulation unit 1073, amultiplexing unit 1075, a radio transmission unit 1077, and an uplinkreference signal generation unit 1079.

The higher layer processing unit 101 outputs the uplink data (thetransport block) generated by a user operation or the like, to thetransmitter 107. Furthermore, the higher layer processing unit 101performs processing of the Medium Access Control (MAC) layer, the PacketData Convergence Protocol (PDCP) layer, the Radio Link Control (RLC)layer, and the Radio Resource Control (RRC) layer.

The radio resource control unit 1011 included in the higher layerprocessing unit 101 manages various pieces of configuration informationof the terminal apparatus 1 itself. Furthermore, the radio resourcecontrol unit 1011 generates information to be mapped to each uplinkchannel, and outputs the generated information to the transmitter 107.

The scheduling information interpretation unit 1013 included in thehigher layer processing unit 101 interprets the DCI (schedulinginformation) received through the receiver 105, generates controlinformation for control of the receiver 105 and the transmitter 107, inaccordance with a result of interpreting the DCI, and outputs thegenerated control information to the controller 103.

The CSI report control unit 1015 indicates to the measurement unit 1059an operation of deriving Channel State Information (RI/PMI/CQI/CRI)relating to the CSI reference resource. The CSI report control unit 1015indicates to the transmitter 107 an operation of transmittingRI/PMI/CQI/CRI. The CSI report control unit 1015 sets a configurationthat is used when the measurement unit 1059 calculates CQI.

In accordance with the control information from the higher layerprocessing unit 101, the controller 103 generates a control signal forcontrol of the receiver 105 and the transmitter 107. The controller 103outputs the generated control signal to the receiver 105 and thetransmitter 107 to control the receiver 105 and the transmitter 107.

In accordance with the control signal input from the controller 103, thereceiver 105 demultiplexes, demodulates, and decodes a reception signalreceived from the base station apparatus 3 through the transmit and/orreceive antenna 109, and outputs the decoded information to the higherlayer processing unit 101.

The radio reception unit 1057 converts (down-converts) a downlink signalreceived through the transmit and/or receive antenna 109 into a signalof an intermediate frequency, removes unnecessary frequency components,controls an amplification level in such a manner as to suitably maintaina signal level, performs orthogonal demodulation on the basis of anin-phase component and an orthogonal component of the received signal,and converts the resulting orthogonally-demodulated analog signal into adigital signal. The radio reception unit 1057 removes a portioncorresponding to a Guard Interval (GI) from the digital signal resultingfrom the conversion, performs Fast Fourier Transform (FFT) on the signalfrom which the Guard Interval has been removed, and extracts a signal inthe frequency domain.

The demultiplexing unit 1055 demultiplexes the extracted signal into thedownlink PCCH, PSCH, and the downlink reference signal, respectively.Furthermore, the demultiplexing unit 1055 makes a compensation ofpropagation channels including PCCH and PSCH from the propagationchannel estimate input from the measurement unit 1059. Furthermore, thedemultiplexing unit 1055 outputs the downlink reference signal resultingfrom the demultiplexing, to the measurement unit 1059.

The demodulation unit 1053 demodulates the downlink PCCH and outputs aresult of the demodulation to the decoding unit 1051. The decoding unit1051 attempts to decode the PCCH. In a case of succeeding in thedecoding, the decoding unit 1051 outputs downlink control informationresulting from the decoding and an RNTI to which the downlink controlinformation corresponds, to the higher layer processing unit 101.

The demodulation unit 1053 demodulates the PSCH in compliance with amodulation scheme notified with the downlink grant, such as QuadraturePhase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), or64 QAM, 256 QAM, and outputs a result of the demodulation to thedecoding unit 1051. The decoding unit 1051 decodes the downlink data inaccordance with information of a transmission or an original coding ratenotified with the downlink control information, and outputs, to thehigher layer processing unit 101, the downlink data (the transportblock) resulting from the decoding.

The measurement unit 1059 performs downlink path loss measurement,channel measurement, and/or interference measurement from the downlinkreference signal input from the demultiplexing unit 1055. Themeasurement unit 1059 outputs, to the higher layer processing unit 101,the measurement result and CSI calculated based on the measurementresult. Furthermore, the measurement unit 1059 calculates a downlinkchannel estimate from the downlink reference signal and outputs thecalculated downlink channel estimate to the demultiplexing unit 1055.

The transmitter 107 generates the uplink reference signal in accordancewith the control signal input from the controller 103, codes andmodulates the uplink data (the transport block) input from the higherlayer processing unit 101, multiplexes PUCCH, PUSCH, and the generateduplink reference signal, and transmits a result of the multiplexing tothe base station apparatus 3 through the transmit and/or receive antenna109.

The coding unit 1071 performs coding on the Uplink Control Informationand the uplink data input from the higher layer processing unit 101. Themodulation unit 1073 modulates the coded bits input from the coding unit1071, in compliance with the modulation scheme such as BPSK, QPSK, 16QAM, or 64 QAM, 256 QAM.

The uplink reference signal generation unit 1079 generates a sequenceacquired according to a rule (formula) prescribed in advance, based on aphysical cell identifier (also referred to as a Physical Cell Identity(PCI), a cell ID, or the like) for identifying the base stationapparatus 3, a bandwidth to which the uplink reference signal is mapped,a cyclic shift notified with the uplink grant, a parameter value forgeneration of a DMRS sequence, and the like.

On the basis of the information used for the scheduling of PUSCH, themultiplexing unit 1075 determines the number of PUSCH layers to bespatial-multiplexed, maps multiple pieces of uplink data to betransmitted on the same PUSCH to multiple layers through Multiple InputMultiple Output Spatial Multiplexing (MIMO SM), and performs precodingon the layers.

In accordance with the control signal input from the controller 103, themultiplexing unit 1075 performs Discrete Fourier Transform (DFT) onmodulation symbols of PSCH. Furthermore, the multiplexing unit 1075multiplexes PCCH and PSCH signals and the generated uplink referencesignal for each transmit antenna port. To be more specific, themultiplexing unit 1075 maps the PCCH and PSCH signals and the generateduplink reference signal to the resource elements for each transmitantenna port.

The radio transmission unit 1077 performs Inverse Fast Fourier Transform(IFFT) on a signal resulting from the multiplexing, performs modulationin compliance with an SC-FDM scheme, attaches the Guard Interval to theSC-FDM-modulated SC-FDM symbol, generates a baseband digital signal,converts the baseband digital signal into an analog signal, generates anin-phase component and an orthogonal component of an intermediatefrequency from the analog signal, removes frequency componentsunnecessary for the intermediate frequency band, converts (up-converts)the signal of the intermediate frequency into a signal of a highfrequency, removes unnecessary frequency components, performs poweramplification, and outputs a final result to the transmit and/or receiveantenna 109 for transmission.

FIG. 18 is a schematic block diagram illustrating a configuration of thebase station apparatus 3 in the present embodiment. As is illustrated,the base station apparatus 3 is configured to include a higher layerprocessing unit 301, a controller 303, a receiver 305, a transmitter307, and a transmit and/or receive antenna 309. The higher layerprocessing unit 301 is configured to include a radio resource controlunit 3011, a scheduling unit 3013, and a CSI report control unit 3015.The receiver 305 is configured to include a decoding unit 3051, ademodulation unit 3053, a demultiplexing unit 3055, a radio receptionunit 3057, and a measurement unit 3059. The transmitter 307 isconfigured to include a coding unit 3071, a modulation unit 3073, amultiplexing unit 3075, a radio transmission unit 3077, and a downlinkreference signal generation unit 3079.

The higher layer processing unit 301 performs processing of the MediumAccess Control (MAC) layer, the Packet Data Convergence Protocol (PDCP)layer, the Radio Link Control (RLC) layer, and the Radio ResourceControl (RRC) layer. Furthermore, the higher layer processing unit 301generates control information for control of the receiver 305 and thetransmitter 307, and outputs the generated control information to thecontroller 303.

The radio resource control unit 3011 included in the higher layerprocessing unit 301 generates, or acquires from a higher node, thedownlink data (the transport block) mapped to the downlink PSCH, systeminformation, the RRC message, the MAC Control Element (CE), and thelike, and outputs a result of the generation or the acquirement to thetransmitter 307. Furthermore, the radio resource control unit 3011manages various configuration information for each of the terminalapparatuses 1.

The scheduling unit 3013 included in the higher layer processing unit301 determines a frequency and a subframe to which the physical channels(PSCH) are allocated, the transmission coding rate and modulation schemefor the physical channels (PSCH), the transmit power, and the like, fromthe received CSI and from the channel estimate, channel quality, or thelike input from the measurement unit 3059. The scheduling unit 3013generates the control information in order to control the receiver 305and the transmitter 307 in accordance with a result of the scheduling,and outputs the generated information to the controller 303. Thescheduling unit 3013 generates the information (e.g., the DCI format) tobe used for scheduling the physical channels (PSCH), based on the resultof the scheduling.

The CSI report control unit 3015 included in the higher layer processingunit 301 controls a CSI report that is made by the terminal apparatus 1.The CSI report control unit 3015 transmits information that is assumedin order for the terminal apparatus 1 to derive RI/PMI/CQI in the CSIreference resource and that shows various configurations, to theterminal apparatus 1 through the transmitter 307.

The controller 303 generates, based on the control information from thehigher layer processing unit 301, a control signal for controlling thereceiver 305 and the transmitter 307. The controller 303 outputs thegenerated control signal to the receiver 305 and the transmitter 307 tocontrol the receiver 305 and the transmitter 307.

In accordance with the control signal input from the controller 303, thereceiver 305 demultiplexes, demodulates, and decodes the receptionsignal received from the terminal apparatus 1 through the transmitand/or receive antenna 309, and outputs information resulting from thedecoding to the higher layer processing unit 301. The radio receptionunit 3057 converts (down-converts) an uplink signal received through thetransmit and/or receive antenna 309 into a signal of an intermediatefrequency, removes unnecessary frequency components, controls theamplification level in such a manner as to suitably maintain a signallevel, performs orthogonal demodulation based on an in-phase componentand an orthogonal component of the received signal, and converts theresulting orthogonally-demodulated analog signal into a digital signal.

The radio reception unit 3057 removes a portion corresponding to theGuard Interval (GI) from the digital signal resulting from theconversion. The radio reception unit 3057 performs Fast FourierTransform (FFT) on the signal from which the Guard Interval has beenremoved, extracts a signal in the frequency domain, and outputs theresulting signal to the demultiplexing unit 3055.

The demultiplexing unit 1055 demultiplexes the signal input from theradio reception unit 3057 into PCCH, PSCH, and the signal such as theuplink reference signal. The demultiplexing is performed based on radioresource allocation information that is determined in advance by thebase station apparatus 3 using the radio resource control unit 3011 andthat is included in the uplink grant notified to each of the terminalapparatuses 1. Furthermore, the demultiplexing unit 3055 makes acompensation of channels including PCCH and PSCH from the channelestimate input from the measurement unit 3059. Furthermore, thedemultiplexing unit 3055 outputs an uplink reference signal resultingfrom the demultiplexing, to the measurement unit 3059.

The demodulation unit 3053 performs Inverse Discrete Fourier Transform(IDFT) on PSCH, acquires modulation symbols, and performs receptionsignal demodulation, that is, demodulates each of the modulation symbolson PCCH and PSCH, in compliance with the modulation scheme prescribed inadvance, such as Binary Phase Shift Keying (BPSK), QPSK, 16 QAM, 64 QAM,or 256 QAM, or in compliance with the modulation scheme that the basestation apparatus 3 itself notifies in advance each of the terminalapparatuses 1 with the uplink grant. The demodulation unit 3053demultiplexes the modulation symbols of multiple pieces of uplink datatransmitted on the same PSCH with the MIMO SM, based on the number ofspatial-multiplexed sequences notified in advance with the uplink grantto each of the terminal apparatuses 1 and information designating theprecoding to be performed on the sequences.

The decoding unit 3051 decodes the coded bits of PCCH and PSCH, whichhave been demodulated, in compliance with a coding scheme predeterminedin advance, with the transmission or original coding rate that ispredetermined in advance or notified in advance with the uplink grant tothe terminal apparatus 1 by the base station apparatus 3 itself, andoutputs the decoded uplink data and uplink control information to thehigher layer processing unit 101. In a case where the PSCH isre-transmitted, the decoding unit 3051 performs the decoding with thecoded bits input from the higher layer processing unit 301 and retainedin an HARQ buffer, and the demodulated coded bits. The measurement unit309 measures the channel estimate, the channel quality, and the like,based on the uplink reference signal input from the demultiplexing unit3055, and outputs a result of the measurement to the demultiplexing unit3055 and the higher layer processing unit 301.

The transmitter 307 generates the downlink reference signal inaccordance with the control signal input from the controller 303, codesand modulates the downlink control information, and the downlink datathat are input from the higher layer processing unit 301, multiplexesPCCH, PSCH, and the downlink reference signal or assign distinct radioresources to them, and transmits a result of the multiplexing to theterminal apparatus 1 through the transmit and/or receive antenna 309.

The coding unit 3071 performs coding on the Downlink Control Informationand the downlink data input from the higher layer processing unit 301.The modulation unit 3073 modulates the coded bits input from the codingunit 3071, in compliance with the modulation scheme such as BPSK, QPSK,16 QAM, 64 QAM or 256 QAM.

The downlink reference signal generation unit 3079 generates, as thedownlink reference signal, a sequence that is already known to theterminal apparatus 1 and that is acquired in accordance with a ruleprescribed in advance based on the physical cell identity (PCI) foridentifying the base station apparatus 3, or the like.

The multiplexing unit 3075, in accordance with the number of PSCH layersto be spatial-multiplexed, maps one or multiple pieces of downlink datato be transmitted on one PSCH to one or multiple layers, and performsprecoding on the one or multiple layers. The multiplexing unit 375multiplexes the downlink physical channel signal and the downlinkreference signal for each transmit antenna port. Furthermore, themultiplexing unit 375 allocates the downlink physical channel signal andthe downlink reference signal to the resource element for each transmitantenna port.

The radio transmission unit 3077 performs Inverse Fast Fourier Transform(IFFT) on the modulation symbol resulting from the multiplexing or thelike, performs the modulation in compliance with an OFDM scheme togenerate an OFDM symbol, attaches the Guard Interval to theOFDM-modulated OFDM symbol, generates a digital signal in a baseband,converts the digital signal in the baseband into an analog signal,generates an in-phase component and an orthogonal component of anintermediate frequency from the analog signal, removes frequencycomponents unnecessary for the intermediate frequency band, converts(up-converts) the signal of the intermediate frequency into a signal ofa high frequency signal, removes unnecessary frequency components,performs power amplification, and outputs a final result to the transmitand/or receive antenna 309 for transmission.

(1) More specifically, the base station apparatus 3 according to thefirst aspect of the present invention, includes a coding unit todetermine the number of code block groups, divide an input bit sequenceto code block segmentation into code block groups of the number of codeblock groups, determine the number of code blocks for each of the codeblock groups, divide each of the code block groups into code blocks ofthe number of code blocks, and apply a channel coding to each of thecode blocks.

(2) In the first aspect described above, the number of code block groupsis determined based on the number of OFDM symbols.

(3) In the first aspect described above, the number of code blocks inthe first code block group is determined based on the number of resourceelements included in one or more OFDM symbols corresponding to the firstcode block group.

(4) In the first aspect described above, the input bit sequence to thecode block segmentation is a bit sequence in which a Cyclic RedundancyCheck (CRC) sequence is attached to the transport block.

(5) In the first aspect described above, the number of OFDM symbols isdetermined based on information indicated by a higher layer or aphysical link control channel.

(6) The terminal apparatus 1 according to the second aspect of thepresent invention, includes a coding unit to determine the number ofcode block groups, divide an input bit sequence to code blocksegmentation into code block groups of the number of code block groups,determine the number of code blocks for each of the code block groups,divide each of the code block groups into code blocks of the number ofcode blocks, and apply a channel coding to each of the code blocks.

(7) In the second aspect described above, the number of code blockgroups is determined based on the number of OFDM symbols.

(8) In the second aspect described above, the number of code blocks inthe first code block group is determined based on the number of resourceelements included in one or more OFDM symbols corresponding to the firstcode block group.

(9) In the second aspect described above, the input bit sequence to thecode block segmentation is a bit sequence in which a Cyclic RedundancyCheck (CRC) sequence is attached to the transport block.

(10) In the second aspect described above, the number of OFDM symbols isdetermined based on information indicated by a higher layer or aphysical link control channel.

(11) The communication method according to the third aspect of thepresent invention, determines the number of code block groups, dividesan input bit sequence to code block segmentation into code block groupsof the number of code block groups, determines the number of code blocksfor each of the code block groups, divides each of the code block groupsinto code blocks of the number of code blocks, and applies a channelcoding to each of the code blocks.

(12) The integrated circuit according to the third aspect of the presentinvention, includes a method for determining the number of code blockgroups, dividing an input bit sequence to code block segmentation intocode block groups of the number of code block groups, determining thenumber of code blocks for each of the code block groups, dividing eachof the code block groups into code blocks of the number of code blocks,and applying a channel coding to each of the code blocks.

A program running on an apparatus according to one aspect of the presentinvention may serve as a program that controls a Central Processing Unit(CPU) and the like to cause a computer to operate in such a manner as torealize the functions of the embodiment according to one aspect of thepresent invention. Programs or the information handled by the programsare temporarily stored in a volatile memory such as a Random AccessMemory (RAM), a non-volatile memory such as a flash memory or a HardDisk Drive (HDD), or another storage system.

Furthermore, a program for realizing the functions of the embodimentaccording to one aspect of the present invention may be stored in acomputer readable recording medium. The functions may be realized bycausing a computer system to read and perform the program recorded onthis recording medium. It is assumed that the “computer system” refersto a computer system built into the apparatuses, and the computer systemincludes an operating system and hardware components such as aperipheral device. Further, the “computer-readable recording medium” mayinclude a semiconductor recording medium, an optical recording medium, amagnetic recording medium, a medium that holds a program dynamically fora short period of time, or another recording medium that can be read bya computer.

Furthermore, each functional block or various characteristics of theapparatuses used in the above-described embodiment may be implemented orperformed on an electric circuit, for example, an integrated circuit ormultiple integrated circuits. An electric circuit designed to performthe functions described in the present specification may include ageneral-purpose processor, a Digital Signal Processor (DSP), anApplication Specific Integrated Circuit (ASIC), a Field ProgrammableGate Array (FPGA), or other programmable logic devices, discrete gatesor transistor logic, discrete hardware components, or a combinationthereof. The general-purpose processor may be a microprocessor, or maybe a conventional processor, a controller, a micro-controller, or astate machine. The above-described electric circuit may be constitutedof a digital circuit, or may be constituted of an analog circuit.Furthermore, in a case that with advances in semiconductor technology, acircuit integration technology appears that replaces the presentintegrated circuits, one or more aspects of the present invention canuse a new integrated circuit based on the technology.

Note that the invention of the present patent application is not limitedto the above-described embodiments. In the embodiment, apparatuses havebeen described as an example, but the invention of the presentapplication is not limited to these apparatuses, and is applicable to aterminal apparatus or a communication apparatus of a fixed-type or astationary-type electronic apparatus installed indoors or outdoors, forexample, an AV apparatus, a kitchen apparatus, a cleaning or washingmachine, an air-conditioning apparatus, office equipment, a vendingmachine, and other household apparatuses.

The embodiments of the present invention have been described in detailabove referring to the drawings, but the specific configuration is notlimited to the embodiments and includes, for example, an amendment to adesign that falls within the scope that does not depart from the gist ofthe present invention. Furthermore, various modifications are possiblewithin the scope of one aspect of the present invention defined byclaims, and embodiments that are made by suitably combining technicalmeans disclosed according to the different embodiments are also includedin the technical scope of the present invention. Furthermore, aconfiguration in which constituent elements, described in the respectiveembodiments and having mutually the same effects, are substituted forone another is also included in the technical scope of the presentinvention.

INDUSTRIAL APPLICABILITY

One aspect of the present invention can be applied to, for example, acommunication system, a communication apparatus (for example, a mobilephone apparatus, a base station apparatus, a wireless LAN apparatus, ora sensor device), an integrated circuit (for example, a communicationchip), a program or the like.

REFERENCE SIGNS LIST

-   1 (1A, 1B, 1C) Terminal apparatus-   3 Base station apparatus-   10 Turbo code internal interleaver-   11, 12 Constituent encoder-   20 Subblock interleaver-   21 Bit collection unit-   22 Bit selection unit-   30 Turbo code internal interleaver-   31, 32 Constituent encoder-   40 Subblock interleaver-   41 Bit collection unit-   42 Bit selection unit-   50 Step of setting transport block size from the channel state and    the number of symbols-   51 Step of performing code block segmentation and CRC attachment-   52 Step of performing channel coding-   53 Step of codeword combining and rate matching-   60 Step of performing code block group segmentation-   61 Step of performing code block segmentation-   62 Step of performing channel coding-   63 Step of codeword combining and rate matching-   70 Step of calculating the number M of codeword bits after rate    matching, from the number of OFDM symbols and the number of resource    elements-   71 Step of calculating the number Y of bits before channel coding,    from the number M of codeword bits-   72 Step of dividing the transport block in units of Y bits, and    calculating the number of bits B″ of each code block group-   101 Higher layer processing unit-   103 Controller-   105 Receiver-   107 Transmitter-   109 Antenna-   301 Higher layer processing unit-   303 Controller-   305 Receiver-   307 Transmitter-   1013 Scheduling information interpretation unit-   1015 Channel State Information report control unit-   1051 Decoding unit-   1053 Demodulation unit-   1055 Demultiplexing unit-   1057 Radio reception unit-   1059 Measurement unit-   1071 Coding unit-   1073 Modulation unit-   1075 Multiplexing unit-   1077 Radio transmission unit-   1079 Uplink reference signal generation unit-   3011 Radio resource control unit-   3013 Scheduling unit-   3015 Channel State Information report control unit-   3051 Decoding unit-   3053 Demodulation unit-   3055 Demultiplexing unit-   3057 Radio reception unit-   3059 Measuring unit-   3071 Coding unit-   3073 Modulation unit-   3075 Multiplexing unit-   3077 Radio transmission unit-   3079 Downlink reference signal generation unit

The invention claimed is:
 1. A terminal device comprising: determinationcircuitry configured to determine a determined number of code blockgroups, wherein the determined number of code block groups is determinedbased in part on transport block size; code block segmentation circuitryconfigured to segment the input bit sequence into a plurality of codeblocks based on a parameter related to a maximum size of each codeblock; and encoding circuitry configured to perform channel encoding ofeach of the plurality of code blocks based on low density parity check(LDPC) coding, wherein the determined number of code block groups isdetermined based in part on the maximum size of each code block, whereina cyclic redundancy check parity bit is attached to each of the codeblocks of the code block groups, and wherein the encoding circuitry isconfigured to report a hybrid automatic repeat request (HARQ)information bit for each code block group indicative of whether all ofthe code blocks of each code block group were correctly received.
 2. Theterminal device of claim 1, wherein the code block segmentationcircuitry is configured to attach a cyclic redundancy check to the inputbit sequence.
 3. The terminal device of claim 1, wherein each cyclicredundancy check provides error detection to the code block to whichthat cyclic redundancy check is attached.
 4. A method for a terminaldevice, the method comprising: determining, by determination circuitry,a determined number of code block groups, wherein the determined numberof code block groups is determined based in part on transport blocksize; segmenting, by code block segmentation circuitry, the input bitsequence into a plurality of code blocks based on a parameter related toa maximum size of each code block; performing, by encoding circuitry,channel encoding of each of the plurality of code blocks based on lowdensity parity check (LDPC) coding, wherein the determined number ofcode block groups is determined based in part on the maximum size ofeach code block, wherein a cyclic redundancy check parity bit isattached to each of the code blocks of the code block groups; andreporting, by the encoding circuitry, a hybrid automatic repeat request(HARQ) information bit for each code block group indicative of whetherall of the code blocks of each code block group were correctly received.5. The method of claim 4, wherein the code block segmentation circuitryattaches a cyclic redundancy check to the input bit sequence.
 6. A basestation device comprising: determination circuitry configured todetermine a determined number of code block groups, wherein thedetermined number of code block groups is determined based in part ontransport block size; code block segmentation circuitry configured tosegment the input bit sequence into a plurality of code blocks based ona parameter related to a maximum size of each code block; and encodingcircuitry configured to perform channel encoding of each of theplurality of code blocks based on low density parity check (LDPC)coding, wherein the determined number of code block groups is determinedbased in part on the maximum size of each code block, wherein a cyclicredundancy check parity bit is attached to each of the code blocks ofthe code block groups, and wherein the encoding circuitry is configuredto report a hybrid automatic repeat request (HARQ) information bit foreach code block group indicative of whether all of the code blocks ofeach code block group were correctly received.
 7. The base stationdevice of claim 6, wherein the code block segmentation circuitry isconfigured to attach a cyclic redundancy check to the input bitsequence.
 8. A method for a base station, the method comprising:determining, by determination circuitry, a determined number of codeblock groups, wherein the determined number of code block groups isdetermined based in part on transport block size; segmenting, by codeblock segmentation circuitry, the input bit sequence into a plurality ofcode blocks based on a parameter related to a maximum size of each codeblock; and performing, by encoding circuitry, channel encoding of eachof the plurality of code blocks based on low density parity check (LDPC)coding, wherein the determined number of code block groups is determinedbased in part on the maximum size of each code block, wherein a cyclicredundancy check parity bit is attached to each of the code blocks ofthe code block groups; and reporting, by the encoding circuitry, ahybrid automatic repeat request (HARQ) information bit for each codeblock group indicative of whether all of the code blocks of each codeblock group were correctly received.
 9. The method of claim 8, whereinthe code block segmentation circuitry attaches a cyclic redundancy checkto the input bit sequence.